ARS | Publication request: Yellow Nutsedge (Cyperus Esculentus) Interference in Peanut (Arachis Hypogaea).

Submitted to: Peanut Science
Publication Acceptance Date: July 8, 2004
Publication Date: August 2, 2004
Citation: Johnson, Iii, W.C., Mullinix, JR., B.G. 2003. Yellow Nutsedge (Cyperus Esculentus) Interference In Peanut (Arachis Hypogaea). Peanut Science. 30:15-19.

Interpretive Summary: Yellow nutsedge is one of the most common and troublesome weeds of peanut. Yellow nutsedge reduces crop yields by competition and allelopathy. Yellow nutsedge tubers also contaminate shelled peanut by passing through cleaning and blanching processes. Field studies were conducted from 1997 to 1999 in Tifton, GA to measure the full-season interference of yellow nutsedge in peanut. 'Georgia Green' peanut was seeded in May each year, and plots wer established immediately after crop emergence. Plots were 1.8 m by 1.8 m replicated six times. Yellow nutsedge plants were counted 28 days after crop emergence in each plot. Parameters measured were peanut yield and yellow nutsedge tuber contamination in harvested peanut. Yellow nutsedge densities ranged from 0 to 169 plants/m2. Regression analysis showed a 25% reduction in peanut yield with a yellow nutsedge infestation of approximately 68 plants/m2. Each yellow nutsedge plant reduced peanut yield by 13 kg/ha. Data also showed a positive linear response between yellow nutsedge density and number of tubers contaminating harvested peanut. Tuber contamination increased by 5190 tubers/ha for every yellow nutsedge plant/m2. Control decisions based strictly on anticipated yield reduction may result in infestations that have minimal effect on peanut yield but produce tubers potentially contaminating harvested peanut. A marketing system that rewards growers for providing peanut free of yellow nutsedge tubers would benefit the entire industry. Positive incentives would compensate growers for the additional inputs needed to control yellow nutsedge beyond the benefits of preventing yield loss.

Technical Abstract: Studies were conducted from 1997 to 1999 at the Coastal Plain Experiment Station in Tifton, GA to measure the full-season interference of yellow nutsedge in peanut using a response prediction experiment with a natural infestation of yellow nutsedge. 'Georgia Green' peanut was seeded in May each year, and plots were established immediately after crop emergence. Plots were 1.8 m by 1.8 m replicated six times. Yellow nutsedge plants counted 28 days after crop emergence in each plot, and six weed-free plots were randomly established. Parameters measured were peanut yield and yellow nutsedge tuber contamination in harvested peanut. Yellow nutsedge densities ranged from 0 to 169 plants m-2. Regression analysis showed a 25% reduction in peanut yield with a yellow nutsedge infestation of approximately 68 plants m-2. Each yellow nutsedge plant m-2 reduced peanut yield by 13 kg ha-1. Data also showed a positive linear response between yellow nutsedge density and number of tubers contaminating harvested peanut. Tuber contamination increased by 5190 tubers ha-1 for every yellow nutsedge plant m-2. These results indicate that yellow nutsedge is a poor competitor with peanut. However, tuber contamination and resulting effects on peanut quality should be considered when using these results in developing treatment thresholds.